Project Summary Suicide is the second leading cause of death for 19- to 34-year-olds and the third leading cause of death for 35- to 54-year olds in the United States. Despite a 24% increase in suicide rates between 1999 and 2014, the field?s ability to predict risk for death by suicide has not improved in the past 50 years, indicating an urgent need for studies to identify novel, specific mechanisms of risk. Given recent evidence that a history of prior suicide attempt (SA) is an even greater risk factor for later completed suicide than previously thought, a key focus should be on factors that increase risk for SA. Although SAs occur transdiagnostically (i.e. across a broad range of diagnoses as well as in the absence of a diagnosable disorder), most research to date has taken a disorder-specific approach to understanding SAs. Further, despite evidence for abnormalities in reward functioning in suicide attempters, little is known about which specific components of reward processing may be most impaired in those with a history of SA, specifically (i.e. anticipatory pleasure, consummatory pleasure, reward learning). In addition, although there is evidence that a number of demographic and other variables are differentially linked with the presence and characteristics of SAs, the potential impact of these variables on reward processing in suicide attempters remains unclear. To address the limitations of prior research, the proposed study will provide a fine-grained transdiagnostic investigation of reward processing in those with and without a history of SA across multiple units of analysis (e.g., electroencephalography/event-related potentials, behavior, self-report). Specific Aim 1 is to take a fine-grained multiple-units-of-analysis approach to examine anticipatory and consummatory reward processing and reward learning in individuals with a history of SA, compared to those without such history. Specific Aim 2 is to determine the specificity of reward-processing impairments to individuals? history of SA versus their current or past histories of psychopathology. Finally, an exploratory aim is to examine the potential moderating roles of sex, sexual orientation, race/ethnicity, and SA characteristics (i.e., single vs. multiple attempt, lethality, and recency of last attempt). The proposed project directly addresses the first of the four Strategic Objectives outlined in the NIMH Strategic Plan 2016 - ?Define the mechanisms of complex behaviors.? The proposed project also has the potential to provide valuable information that is in line with the fourth NIMH Strategic Objective ? ?Strive for prevention and cures.? Indeed, identification of specific reward system disruptions in suicide attempters might provide important information needed to improve intervention or prevention efforts with this specific, extremely high-risk population.